I'm always on the hunt for an antique bone ruler, but rarely do I find one in good condition that doesn't cost a fortune--even rarer that I come across one that folds out to two feet. I found a mark on it reading "No 60" but no makers name. A lovely thing, and quite usable still, with the numbers and 16th of an inch marks on the interior side all still entirely clear and dark.
24 inches long; folded 6 3/8" x 1" x 3/8". Very good condition, with all joints folding and unfolding smoothly. C. 1880s I believe.